Question

9.9乘6.6+3.3×10.2的简便方法？

Answer 1

9.9×6.5+6.6×3.5-6.5×3.3
=9.9×6.5+6.5×3.5-6.5×3.3+3.5×0.1
=6.5×（9.9+3.5-3.3）+0.35
=6.5×（10+0.1）+0.35
=65+0.65+0.35
=66
另一种
9.9×6.5+6.6×3.5-6.5×3.3

=(3.3 + 6.6) x 6.5 + 6.6 x 3.5 - 6.5 x 3.3
= 6.5 x 3.3 + 6.5 x 6.6 + 6.6 x 3.5 - 6.5 x 3.3
= 6.5 x 6.6 + 6.6 x 3.5
= (6.5 + 3.5 )x 6.6
=10 x6.6
=66

Answer 2

9.9×6.6+3.3×10.2
=（3.3×3）×6.6+3.3×10.2
=3.3×（3×6.6）+3.3×10.2
=3.3×19.8+3.3×10.2
=3.3×（19.8+10.2）
=3.3×30
=99